I have a Rheem gas water heater 21Br40-7T.

I have a STRONG odor when (for example) someone is taking a shower and running the gas dryer. It's so strong that it burns my eyes so bad.

Does anyone know what it could be and how to fix it?

Thank you.
Kelli

Strong odor as in? Exhaust smell? Gas smell? Sewer?

More of an exhaust smell.

Kelli

Sounds like you have a possible venting issue. Make sure vent is open to the roof. Is the vent a single vent or paired with another vent?

You may need a fresh air supply for the dryer if the house is tight. I have seen this happen before on this forum.

Taking a shower would indicate that the HW heater is running and using the gas dryer at the same time may overload the vent or have insufficient make up air as Dr Tom indicated.

Run a piece of 6" flex into the attic to a 6x8x6 sheet metal boot on each end with a simple stamped grill on it. One end goes where the dryer is located and the other end under the eave. Place a piece of screen on the eave end to keep out bugs.You will get plenty of make-up air through this vent. If the hot water heater is in another room place one there, too. It's required in many states for a gas hot water heater, furnace, or gas dryer to prevent what is happening now as it can cause carbon monoxide poisoning or an explosion of methane (sewer) gas. I refuse to install a gas appliance without make-up air because it's foolish and it's the law. You need one for each room where there is a gas appliance. Here are the official requirements: https://dl.dropbox.com/u/8010163/Make-up%20Air%20for%20Gas%20Appliances.zip
How someone could install gas appliances without make-up air is beyond me because that person can be sued and forced to install make-up air plus any damages. It is mandatory per federal laws.